Three Colorado moviegoers who were wounded when a gunman opened fire at a July screening of The Dark Knight Rises on Friday sued the owner of the theater, Cinemark USA, accusing it of failing to provide adequate security.

"Readily available security procedures, security equipment and security personnel would likely have prevented or deterred the gunman from accomplishing his planned assault on the theater's patrons," the law firm of Keating, Wagner, Polidori and Free said in a written statement.